An absorbent article such as a pants-type disposable diaper and the like generally includes such members as waistline portions for the wearer's waistline (specifically, a front waistline portion and a back waistline portion), a crotch portion for the wearer's crotch, and an absorber which absorbs excretion discharged from the wearer. The pants-type diaper is provided with leg-surrounding portions where openings for inserting wearer's legs are formed. Each of the leg-surrounding portions is provided with a leg gather formed with a string-like rubber to fit the leg-surrounding portion to the wearer.
In a manufacturing process of such a pants-type diaper, a web including a continuum of the members described above is conveyed using conveying belts and the like. In a web folding step, a web is folded into two in the cross direction CD orthogonal to the machine direction MD so that a continuum of front waistline portions and a continuum of back waistline portions can be overlaid one another, while the web is being conveyed in the machine direction MD, that is, in a flow direction of the manufacturing process (Patent Document 1, for example). In this step, the front waistline portions and the back waistline portions are overlaid one another with reference to a folding line parallel with the machine direction on a non-continuum of the crotch portions discontinuously provided between a continuum of the front waistline portions and the back waistline portions (near a center, for example).
Next, in a web joining step, the front waistline portions are joined to the back waistline portions at a predetermined intervals by using a joint apparatus provided with a ultrasonic horn, while the web folded in two are continuously being conveyed in the machine direction (Patent Document 2, for example). Then, in a cutting step, the web is cut into individual pants-type diapers by using a cutting apparatus provided with a cutting blade.
In the web folded into two, the crotch portions are discontinuously provided in the machine direction, and are therefore conveyed by following conveyance of the continua of the front waistline portions and the back waistline portions. Also, in the web folded into two, a leg gather is provided on each of the leg-surrounding portions.
Accordingly, if no restrictions are applied to the web, there is a problem that the non-continuum of the crotch portions is likely to contract in a direction toward the continua of the front waistline portions and the back waistline portions, and in particular, the vicinity of the leg-surrounding portions provided with the leg gathers is likely to contract in a direction toward the continua of the front waistline portions and the back waistline portions.
In order to prevent the web from having creases due to contraction, a belt conveyor for conveying the web employs a suction belt configured to attract the web by means of the suction power. However, there is a problem that a defect such as a crease is likely to occur on the web since the web gets away from the belt conveyor at locations where the web is handed over from a belt conveyor to another apparatus (for example, the joint apparatus or the cutting apparatus described above).